The remains of the Castle can be visited
Richstein Castle (Ruin)

The Richstein Ruin, once a hilltop castle, stands above the village of the same name in North Rhine-Westphalia.
History+
The construction of Richstein Castle is dated to the second half of the 14th century. Its first documented mention occurred in 1384, when Landgrave Hermann II of Hesse granted the castle as a fief to Count Johann I of Sayn-Wittgenstein. This feudal relationship was confirmed multiple times in 1416, 1427, and 1490. As early as 1415, bailiffs of the Counts of Sayn-Wittgenstein resided at the castle. In 1502, Count Wilhelm the Elder of Sayn-Wittgenstein designated the complex as a dower house for his wife Johannetta of Isenburg. After the castle's military significance waned, it fell into disrepair in the second half of the 16th century.
Source: Wikipedia · Licence: CC BY-SA 4.0
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 50.9852, 8.4580